Agricultural crops are typically classified as row crops or solid seeded crops. Row crops such as corn, sunflowers, and the like are planted in relatively widely spaced rows, typically about 20-36 inches apart, while solid seeded crops such as wheat, barley, and the like are planted in narrowly spaced rows that are typically only 6-12 inches apart. Once seeded, the spaces between the rows in row crops may be cultivated, and the rows of plants may be sprayed with chemicals etc., and the harvesting equipment for row crops is typically designed to harvest the individual rows. In contrast once seeded, the rows in solid seeded crops are generally ignored and further operations take place generally without regard for the rows.
As a result seeding implements used for seeding each have been quite different. A typical row crop planter has individual planting units spaced across the width of a planter frame, and each planter unit has its own furrow opener, packer, seed container, and metering system for metering seeds from the container down into the furrow opener. In addition many row crops benefit from singulation metering where the metering system drops the seeds one by one down to the furrow opener so that the plants growing from the seeds are substantially equally spaced along the seed row at some selected desirable spacing. In air seeders for row crops, a small seed container on each planting unit is supplied with seed on demand or nursed from the central seed container typically carried on a separate cart.
In contrast in a typical implement for seeding solid seeded crops, a single seed container serves a whole section of furrow openers. In the earlier prior art the seed container extended along the width of the implement with furrow openers mounted under the container. A grooved roller or wheel in the bottom of the container above each furrow opener rotated and so seeds from the container filled the grooves and as the roller rotated it dropped the seeds in bulk down to the furrow opener, rather than singly. Present day air seeders typically have a central seed container with a bulk meter at the bottom, typically again comprising a grooved roller or auger, which feeds seeds in bulk into an air stream which carries the seeds through a network of conduits to each furrow opener.
Popular and profitable row crops such as corn and soybeans typically require a longer growing season than solid seeded crops like wheat and barley, and so have not been grown in agricultural areas with shorter growing seasons such as the northern plains of North America, and in particular Canada. Research and plant breeding is developing newer varieties which mature more quickly, extending the viable agricultural areas for such crops northward. Temperatures also appear to be trending upward which could lead to a corresponding increase in the length of the growing season. Farmers in areas where traditionally only solid seeded crops were grown have an interest in planting these row crops however the seeding implements used for solid seeded crops are not suitable for row crops. Seeding these row crops in more narrowly spaced rows such as are used for solid seeded crops reduces the yield potential and so is not a desirable option. Also solid seeded seeding implements do not have the capability to deliver seeds to the furrow openers one at a time. Purchasing a separate seeding implement for row crops is a considerable expense and so many farmers are reluctant to invest in additional equipment to start seeding row crops.
Case IH™ manufactured a Concord™ air seeder for planting both row crops and solid seeded crops using the Cyclo Air™ meter. The meter dispensed singulated seeds, however instead of dropping the seeds into one furrow opener as in a typical singulating meter, the Cyclo Air™ system distributed the singulated seeds dispensed from the meter into up to eight spaced apart furrow openers with differing delivery tube lengths. Achieving consistent seed spacing in each row with this system is problematic.
U.S. Pat. No. 7,765,943 to Landphair et al. discloses a metering device for mounting above a furrow opener that includes a singulating side and a volumetric or bulk metering side. Seed from a seed source is received by the device and a gate directs the seed either to the singulating side or the bulk metering side, and the metered seed drops out of an aperture in the bottom of the device to the furrow opener.